Prevalence of High Corneal Astigmatism in Native American Infants and Toddlers

Abstract

 

Abstract:

 

Previous research has documented a high prevalence of corneal astigmatism among children of some Native American Tribes. However, little is known about prevalence of astigmatism in Native American children prior to the preschool years. We compared prevalence of high corneal astigmatism in Native American infants and toddlers from a tribe in which a high prevalence of corneal astigmatism has been documented in older children to prevalence in a sample of non–Native American infants and toddlers.

 

Subjects ranged from 6 months to < 3 years of age. A predominantly Native American (NA) sample of infants and toddlers was recruited for participation during WIC clinics conducted on the Tohono O'odham reservation, and a predominantly Caucasian non–Native American (Non–NA) sample of infants and toddlers was recruited through local birth announcements (Tucson, AZ). We attempted to obtain right eye corneal astigmatism measurements with the Infant Keratometer (IK2), a hand–held keratoscope that records digital video of the corneal reflection of a ring of LEDs mounted on the front of the instrument. Corneal astigmatism measurements are determined by computerized analysis of single frames of focused centered images.

 

We obtained 3 scoreable images on 25/43 (58%) NA children and on 12/17 (71%) Non–NA children. Mean age of NA (19.35 mos) and Non–NA children (19.56 mos) on whom measurements were obtained did not differ significantly. The median of 3 corneal astigmatism measurements was determined for each child. There was a significantly higher prevalence of high corneal astigmatism (≥ 2.00 D) among NA children (44% ) than Non–NA children (0%) (Fisher Exact Test, p < 0.01).

 

 

^{There is a high prevalence of high corneal astigmatism in this population of Native American infants and toddlers. Longitudinal studies are needed to determine changes in astigmatism in early development, and the consequences of this early uncorrected astigmatism on visual development.}

 

 

Keywords: astigmatism • refractive error development